NEW: Adams Arms P Series ADJUSTABLE Micro Gas Block

A couple of months ago Adams Arms has introduced their P Series Micro Gas Block which you can read about by clicking here. Recently, they have also announced the availability of the adjustable version of that gas block called P Series Adjustable Micro Gas Block.

Just like the previous model, it replaces the standard AR-15 gas block and in conjunction with the Adams Arms gas piston, it converts the rifle into a short stroke gas piston operated one. It is a low profile gas block, which means it should fit many of the handguards available on the market. It is designed to fit the .750 barrel diameter at the gas block mounting portion. This gas block also has five adjustability settings allowing 100%, 74%, 53%, 32%, and 11% of gas flow.

The Adjustable Micro Gas Block weighs 3.89 oz and it is compatible with the Adams Arms piston system only. It is available through Adams Arms website at an MSRP of $195.99.

If you are not familiar with Adams Arms gas piston system, watch the video below.

I think the short stroke gas piston operation is a great system. However, it is not necessarily good for the rifle that is originally designed to be a DI one. There are pros and cons for both systems. So before even choosing a piston system, you need to make up your mind whether you think converting the AR-15 into a piston operated rifle is a good idea or not.

To convert, or not to convert, that is the question!

Hrachya H

Being a lifelong firearms enthusiast, Hrachya always enjoys studying design, technology and history of guns and ammunition. His knowledge of Russian allows him to translate and make Russian/Soviet/Combloc small arms related information available for the English speaking audience.
Should you need to contact him, feel free to shoot him a message at


  • Machinegunnertim

    I’ve been using A.A. piston systems for 7 years+ now and they have never failed to operate. I own 3 uppers now and 3 kits awaiting assembly. My 5.45×39 gun has seen the most rounds and that’s all corrosive 7n6. The system is especially advantageous for suppressor user like myself.

    I carried multiple M16A2’s and M16A4’s and i have no doubts of the reliability of the D.I. system, I just like the piston more. There has been no carrier tilt, higher recoil or whatever dreaded effects that people whine about, just clean smooth shooting.

    The author poses the question, “To convert, or not to convert”. Now days i would generally say don’t convert. Build it as a piston from parts or buy an A.A. upper. As cheap as AR parts are now it’s more economical to do it that way.

    • Wolfgar

      Sorry, there is more recoil. Shoot a DI next to a AA piston rifle and you will understand the advantage of the DI system. That said, the Adam Arms is a great piston system for suppressed rifles and with the smaller lighter gas block will make a great piston conversion for those who want one. The AA piston system is self regulating and works great with over gassed barrels. The carbine length piston has less recoil compared to the mid length piston in my experience.

      • Machinegunnertim

        It all depends on the over all setup, I started my hobby with a Model 1 Sales carbine kit 13 years ago and that thing recoiled way harder than any of my piston guns. Even with a Spikes heavy buffer.

        I think if your expecting more recoil your mind convinces you it’s there. If your convinced, I’d like to see data on how much recoil there is between two identical guns, one with the piston and one with D.I.

        • Wolfgar

          I shoot competitively and I have never seen a piston AR used by any top competitor. If your DI had more recoil it was over gassed. It is easy to test recoil by how fast your follow up shots are made by using a timer. The lower the recoil the faster your split times. Sorry the DI rules in the recoil department.

          • Machinegunnertim

            I’ve seen a lot of FN SCAR’s in competition. Speed of follow up shots is likely not the reason why top competitors don’t use it though. D.I. is not superior in the recoil dept. it’s the fact that it’s more tune-able that the piston is why you see competitors using it more. Sorry.

          • wolfgar

            I have not seen a lot of FN scars in competition or any other place. If the very expensive FN was faster than the AR DI system the AR would fall to way side in competition. Competitors,”including myself” will use what ever works the best. If the DI is more tun-able, then it has less recoil proving my point.. I’m not trying to argue but geesh!

    • Adam D.

      What handguards are you running?
      I like the Adams system, especially this new, smaller and lighter gas block,
      but as far as I know, modern, thinner style handguards like the BCM, UTG Pro, Centurion Arms etc. don’t fit without modifications to the barrel nut/rail or the oprod bushing.

      • Machinegunnertim

        I’m using Magpul MOE mid and rifle length as well as the Samson EVO rail on the EVO Ultralight. I wanted to build my own ultra light and have been searching for an M-lok free float rail for ages that will fit.
        I finally found one that will, the Ergo Superlite from Ergo Grips is designed to fit an A.A. piston system. A woman at the company told me so over the phone but I would double check on that.

        You may have also noticed that A.A. just released there own M-lok rails that are essentially the same thing only a scant amount lighter than the Ergo version.
        They should have done this long ago.

        • Adam D.

          I see,thanks!
          Yeah, one of the detriments of using a piston system.
          You’re basically stuck with a few options and that’s it.
          The MOE models are still the best in the polymer handguard field
          (not much competition though, only the B5 and the Springfield-BCM ones aside from the old mil-spec stuff), but they are too bulky.
          Didn’t know about the Ergo and the AA offerings.
          Samson has a very promising new rail as well, but I don’t know if it still fits AA systems.

  • Isaac O. Lees

    Of all the gun accessories with no point, AR piston conversions may be the most pointless.

    To borrow a term from the vatniks: rifle is fine.

  • Big Daddy

    I’m waiting for someone to do that with a DI gas block. They do make adjustable and they don’t seem robust. I had a Spikes that never worked well a few years ago. What’s so hard about this it’s a rotating bolt/pin with holes in it.

    • Machinegunnertim

      Write to A.A. maybe they can get the Voodoo Innovations side to make it.

    • Organgrinder

      Try a block from Odin Works, the click detented Inconel valve screw grabbed my attention.

  • Ryan L

    I went with a huldra (mills fleet farm adams rebrand) piston upper as my first AR. I don’t have a ton of experience with ARs but I do love the cleanup after a range session being so easy.

  • Josh d

    I have been running an AA piston upper on my primary ar since 2011. No ar is as comfortable for me to shoot as this one has been short of a very tuned race gun. Recoil on my AA parts kit lower with standard buffer, mid length gas on 14.5barrel, and a2 birdcage is the same as my friends stock mp15 with carbine gas. The impulse is notably different but not any more dramatic than a bone standard ar15. Putting a comp and hydraulic or jp silent buffer, would make it substantially nicer im sure but my rifle with 70 dollar stag lower cost me 700 on a black Friday sale. The barrel finish is still great besides being dropped and dragged, shot more than 4000 rds in the desert with a couple hundred indoors. The stock piston return spring is still good, the buffer spring is still good, the bolt spring is good. Easy as hell to clean which is nice when you go from dumping rounds to it being dropped in sand and needs to be cleaned. Minus the gas block, everything stays cool enough to handle without burning after sustained fire.

    That’s about everything I can think of to say about it.

  • Greg Anderson

    Somewhat surprised there isn’t a 0% setting.

    • Russ Kell

      Looking at the setting on the front of the block, if it is like their 5 Position XLP block, it looks like one more click to the right would be ‘off’. Can’t say for certain and their own site doesn’t say.

  • MissileMech

    I still like the Superlative Arms piston kit mo better with its 30 positions. I don’t know about recoil, but mine functions very smoothly. IMHO.

  • organgrinder

    Now if they’d only fit that gas plug w/a straight DI AR gas tube cut to fit a mid-length system.

  • Sledgecrowbar

    Fpr $200 that doesn’t include the majority of the conversion, Adams Arms is smoking some bad weed laced with bad crack. I figured this was their revision attempt at making a GB to fit under NSR handguards since their first low profile GB does not and everyone else’s piston kits do, but this is now equivalent to the street price of their entire kit. I’m not buying it twice when I can buy a Superlative once.

  • Russ Kell

    Second that vote for SLR. Work excellent on suppressed setups as well.